1. Field of the Invention
The present invention relates to a thermal print head for thermal recording and a method for manufacturing the same.
2. Description of the Related Art
In conventional thermal print heads which perform thermal recording through selective heating of heating elements, only the heating elements are formed on an insulating substrate of ceramics or quartz, that is, they are formed separately from a print driver circuit section. The individual resistance elements are connected to the driver circuit section by wire-bonding or the like. In these thermal print heads, a drive signal is supplied from the driver circuit section to each resistance element through a wire, whereby the resistance elements are selectively heated so that a thermal ink sheet is heated to effect thermal printing on a recording sheet.
If the print dot pitch is fine, according to the thermal print heads of this type, the spaces between wiring conductors, which are connected to the heating elements, are so narrow that the heating elements and the print driver circuit section cannot be easily connected. Accordingly, the wiring conductors of the print head are fanned out from the heating-element side so that their extended portions are connected to the driver circuit section by wire-bonding. However, the wire-bonding is not a highly efficient method of connection, and the thermal print heads must be large-sized.
According to the wire-bonding method, moreover, bonding regions are protuberant. Since there is hardly any allowance for deformation after the bonding regions are sealed by means of resin, the configuration of the resulting assembly must be maintained before the bonding. Thus, the assembly work is a hard task, and the reliability of the products is lowered after prolonged use.
Recently, therefore, a novel arrangement has been proposed such that heating elements and print driver circuit elements for heating the heating elements are formed together on one and the same insulating substrate.